JPS638534B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording/reproducing device capable of high track density writing.

There is an azimuth recording method that has been used in VTR devices and the like as a method that enables high track density writing. In other words, by helical scanning a magnetic tape wrapped around a rotary head cylinder equipped with two magnetic heads each having a gap azimuth in the writing track width direction, a high density can be achieved without providing a guard area between each track. This is a method of track writing. In these methods, since adjacent tracks can be recorded and reproduced using magnetic heads with different gap azimuths, there is no interference between adjacent tracks due to the azimuth loss effect during the reproduction process. As a result, each track can be recorded close to each other or overlapping each other to some extent without using a guard area.

As a method for applying azimuth recording to a magnetic disk device, the method shown in FIGS. 1 to 3 has already been proposed (Japanese Patent Laid-Open No. 53-120415). FIG. 1 is a plan view showing the floating surface of a floating head 1a used in a magnetic disk device, in which 2 is a slider, 3a and 3b are magnetic heads fixed to the slider 2, and parallel to this with a center line 5a in between. The two magnetic heads are kept in contact with each other with a distance D such that magnetic leakage between the magnetic heads can be ignored. FIG. 2 is a side view showing the relative positional relationship between the floating head 1a and the magnetic disk 6 during operation. The floating head 1a floats on a magnetic disc 6 that rotates at high speed in the direction of an arrow 7, and the head gaps 4 of the magnetic heads 3a and 3b
Distances a and 4b from the rotating magnetic disk surface, respectively
It floats stably in balance with the head load (not shown in the figure) in a posture such that Ha and Hb.

FIG. 3 is a plan view showing the state of data tracks recorded on the magnetic disk 6 by the floating head 1a.

The center line 5b of the floating head 1a is connected to the magnetic disk 6.
The floating head 1a is fixed on the carriage so as to overlap a center line 8 passing through the center C of the carriage, and the carriage is arranged to move the floating head 1a radially along the center line 8. First, the magnetic heads 3a and 3b generate a track a.
1 and b1 are recorded, and then the floating head 1a moves radially along the center line 8 until the magnetic head 3a overlaps track a2, at which position tracks a2 and b2 are recorded. In this way, the data track area on the magnetic disk 6 is sequentially
3, b3, . . . , (a(N)), (b(N)) data tracks are recorded. The head gaps of the magnetic heads 3a and 3b for writing each data track have azimuth angles α and β, respectively, with respect to the center line 8 of the magnetic disk 6, so that the magnetic heads 3a and 3b that write each data track have azimuth angles α and β, respectively. The upper magnetization direction forms an angle α+β, which enables high track density writing with little interference between tracks.

In the conventional example described above, in order to reduce magnetic leakage, the magnetic heads 3a and 3b are provided along the center line 5a and separated by a distance D, but as shown in FIG. In order to float while maintaining a constant angle with the surface of the plate 6, the floating distance of the gap 4a, 4b of each magnetic head is
Ha and Hb are also very different (Ha<Hb).

As a result, there is a drawback in that a wide difference (variation) occurs in the recording and reproducing characteristics between the magnetic heads 3a and 3b.

In addition, although it was assumed that the floating head 1a is fixed on the carriage so that the center line 5b of the floating head 1a and the center line 8 of the magnetic disk 6 overlap, it is thought that the floating head 1a is generally fixed at an angle of a small angle θ. There must be. In this case, track a(N) will deviate from the normal position with respect to track b(N) by Dsinθ. Now, D=3mm, θ
= 1°, then Dsinθ≒0.052mm, and if we consider the case of narrow track writing with writing track width Tw = 0.05mm, track a(N) and track b(N) are almost completely overlapped. This is a very unfortunate result. Truck a (N)
Even if the deviation of track b (N) from the normal position is allowed up to 10% of the track width Tw, the angle restriction for mounting the head is θ=
An accuracy of 0 degrees ± 6 minutes is required. It is extremely difficult to carry out such highly accurate regulation both from the standpoint of manufacturing the floating head 1a and from the standpoint of mounting accuracy to the carriage, and has also been a problem from a practical standpoint.

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional ones, and it is possible to use at least one magnetic recording medium, such as a magnetic disc or a magnetic tape, with different azimuth angles on a line substantially orthogonal to the running direction of a magnetic recording medium such as a magnetic disc or a magnetic tape. It is characterized in that two magnetic heads are arranged as a set, and the arrangement pitch of these magnetic heads is an integer multiple of 3 or more than the track pitch formed on the magnetic recording medium. This reduces variations in the recording and reproducing characteristics between magnetic heads, and enables high track density recording using the azimuth recording method, which is highly practical in terms of magnetic head manufacturing and magnetic head installation accuracy. The purpose is to provide a magnetic recording and reproducing device.

An embodiment in which the present invention is applied to a magnetic disk device will be described below with reference to FIGS. 4 to 6. FIG. 4 is a plan view showing the floating surface of the floating head 1b, FIG. 5 is a side view showing the relative positional relationship between the magnetic disk and the floating head in an operating state, and FIG. 6 is a view showing the recording tracks recorded on the magnetic disk. FIG. In FIG. 4, 1b is a floating head in this embodiment, and a magnetic head 3 with a track width Tw
a, 3b are fixed to the slider 2 so that the distance P between their centers is P=3Tw, and the head gaps 4a, 4b are on a line 5c perpendicular to the traveling direction of the magnetic disc 6. Further, the head gaps 4a and 4b have azimuth angles α and β, respectively, with respect to a line 5c perpendicular to the running direction of the magnetic disk 6.

The floating state of the floating head 1b during operation is:
Due to the air flow along the surface of the magnetic disk 6 rotating at high speed in the direction of arrow 7, the floating head 1b floats at an inclination such that it is wide on the air inflow side and narrow on the air outflow side, and the head load (in the figure) is (omitted).
However, the gap 4a of the magnetic heads 3a, 3b,
4b is a line 5 perpendicular to the running direction of the magnetic disk 6
Since the head gaps 4a and 4b are arranged on the same plane as shown in FIG.
Both b float at a constant floating distance H. As a result, variations in magnetic recording and reproducing characteristics between the magnetic heads 3a and 3b can be reduced. Next, the configuration of the tracks recorded on the magnetic disk 6 will be explained using FIG. 6. Floating head 1b has head gap 4
It is fixed on a carriage (not shown in the figure) so that the line 5c connecting a and 4b almost overlaps with the center line 8 passing through the center of rotation C of the magnetic disk 6, and can be moved along the center line 8 of the magnetic disk 6. . First, tracks a ₁ and b ₁ are recorded by the magnetic heads 3a and 3b, respectively, at the outermost circumferential position. Next, the floating head moves toward the inner circumference by a track pitch T _p of 2
After moving twice the distance, tracks a ₂ and b ₂ are recorded. Furthermore, the floating head 1b moves inward in steps of 2Tp and repeats the operation of recording tracks a ₃ and b ₃ to record all tracks up to a(N) and b(N).

Looking at the track configuration recorded on the magnetic disk 6 through the above steps, one track corresponds to each of the inner circumferential side of the outermost track _a1 and the outer circumferential side of the innermost track b (N) (two tracks in total). It can be seen that there are areas e and f where only a portion cannot be recorded. However, except for this point, similar to the conventional example shown in FIG. 3, adjacent tracks are composed of tracks recorded with head gaps 4a and 4b having different azimuth angles, and azimuth recording with little interference between tracks is possible. It can be seen that high track density recording is possible. In addition, the number of tracks e and f that cannot be recorded is the track pitch T _p in this example.
and is always 2 regardless of the width W of the recording area. Therefore, in the case of high track density writing such as the one in question, for example, W = 25.4 mm, T _p =
0.0254mm (i.e. track density 1000TPI,
In the case of TPI (Tracks per inch), the unrecordable track area is only 0.2 of the total track area W.
It can be seen that it is only %, which is completely negligible. Furthermore, in the floating head 1b according to the embodiment shown in FIG. 4, the magnetic heads 3a and 3b are separated from each other by a center-to-center distance P=3Tw, so that magnetic leakage between the cores is also reduced.

Although the above embodiment describes the case where it is applied to a magnetic disk device, the present invention can also be applied to a magnetic tape recording device or a magnetic sheet device in which the magnetic head can move in a direction (up and down) perpendicular to the running direction of the medium. Exactly the same effect can be obtained. Further, in the above embodiment, the magnetic heads 3a, 3b
We have described the case where _the distance _P between the centers of
2, 3, ...), the same effect as above can be obtained. In this case, the number of tracks that cannot be recorded is 2N.

An example of the case where N=2, that is, P=5T _p, is applied to a magnetic tape head is shown in FIGS.
It is shown in FIG. FIG. 7 is a front view showing the tape facing surface of the magnetic tape multihead 1c, 3a and 3b.
is a magnetic head, 4a and 4b are head gaps, 9
is the housing. FIG. 8 is a side view showing the positional relationship between the tape 10 and the multihead 1c during operation. Since the head gaps 4a and 4c are on the line 5c perpendicular to the running direction of the tape, the contact with the tape is uniform and the head gap with the tape is uniform. Variations in characteristics between the magnetic heads 3a and 3b due to poor contact are improved. FIG. 9 is a diagram showing the structure of tracks recorded on the magnetic tape 10 by the multihead 1c. Tracks a ₁ , a ₂ , ..., a(N) are tracks recorded by the magnetic head 3a,
Tracks b ₁ , b ₂ , ..., b (N) are magnetic head 3
This is the track recorded by b. P=5T _p
In the case of
For example, in the case of high track density (1000 TPI) recording where Tp is 25.4 mm and T _p =0.0254 mm, the area that cannot be recorded is approximately 0.4% of the total area, which is no problem at all.

Furthermore, in the above embodiment, a case was described in which recording was performed using two azimuth heads 3a and 3b (one set) for the width W of one recording area, but considering two recording areas on one magnetic recording medium. It is also possible to record by moving four azimuth heads (two sets) corresponding to each recording area. In this case, although the number of magnetic heads increases, the advantage is that the number of moving steps for multiheads (including floating heads) can be halved. In addition, the number of divisions of the recording area can be arbitrarily selected.

Furthermore, in the above embodiments, the track width _TW of the magnetic heads 3a and 3b has been described as being equal to the track pitch _Tp recorded on the magnetic recording medium.
It goes without saying that the effects of the present invention can be exerted even in cases where T _w > T _p or T _w < T _p .
When T _w > T _p , the azimuth recorded tracks overlap, and when T _w < T _p , a guard band is created between each track, but since both are azimuth recording, there is no interference between the tracks. There is no.

As described above, the present invention arranges each magnetic head constituting a multi-head at intervals of approximately an integer multiple of 3 or more of the track pitch T _p in a direction approximately perpendicular to the running direction of the magnetic recording medium, and in parallel with each other. The multi-head is configured to be arranged in directions with different head gear azimuths, and is equipped with a head moving device that moves this multi-head in the track width direction in steps twice the track pitch _Tp ,
Although it is possible to realize an orderly and high-density track configuration over almost the entire recording area of a magnetic recording medium, except for a very small part of the recording area, there are variations in recording and reproducing characteristics between magnetic heads and magnetic leakage between cores. Furthermore, since the interference between tracks is small, a magnetic recording/reproducing device with a multi-head structure and a head moving mechanism easy to fabricate can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the floating surface of a conventional floating head for a magnetic disk device, FIG. 2 is a side view showing its operating state, and FIG. 3 is a plan view showing the configuration of recording tracks on the magnetic disk. , FIG. 4 is a plan view showing the floating surface of a floating head in an embodiment in which the present invention is applied to a magnetic disk device, FIG. 5 is a side view showing its operating state, and FIG. Plan views showing the configuration of recording tracks, FIGS. 7 and 8
FIG. 9 is a front view of a head in another embodiment of the present invention applied to a magnetic tape device, respectively.
FIG. 3 is a plan view showing an operating state and a plan view showing the configuration of recording tracks on a magnetic tape. In the figure, 1a and 1b are floating heads, 1c is a multihead, 2 is a slider, 3a and 3b are magnetic heads, 4a and 4b are head gaps, and 5c is a 2
A center line passing through the head gaps of the magnetic heads and substantially orthogonal to the running direction of the magnetic recording medium; 6 a magnetic disk; 7 an arrow indicating the direction of movement of the magnetic disk; 8 a center line of the magnetic disk; 10 is a magnetic tape. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. Consists of a plurality of magnetic heads in a set of two, and the magnetic heads in the set are spaced apart from each other by approximately (2n+1) times the track pitch (where n is a natural number) and are arranged in different directions. A multi-magnetic head is arranged to have a gap azimuth, and the head gaps of the plurality of magnetic heads are substantially in a straight line; 1. A magnetic recording and reproducing apparatus comprising: a head moving mechanism that holds the head in the direction perpendicular to the track pitch and moves the head in the orthogonal direction in steps twice the track pitch. 2. The magnetic recording and reproducing apparatus according to claim 1, wherein the multi-head is a floating head.